Safety pin to be actuated by a magnetic key

ABSTRACT

A safety pin and magnetic key to actuate, loosen or tighten the pin, which incorporate means to automatically and by magnetic attraction connect a body of a cavity of a head of the pin, formed by a fixed part of a rod and by a movable part, by applying the key. The safety head of the pin delimits a totally closed cavity for a body of magnetic material, enabled to slide axially inside the cavity, provided with lateral locking means cooperating with means of the body, which is pressed against a bottom of the cavity by a spring supported by an upper base of the movable part, having external blind orifices for eyebolts of the key. The latter incorporates in a tubular body a permanent magnet on its extremity, with eyebolt support for insertion into the blind orifices and applying simultaneously a magnetic force through the support to the base of the movable part. This permits to attract the body of the cavity and to lock the parts of the head in order to apply an actuating torque on the pin.

TECHNICAL FIELD

[0001] The present invention refers to a safety pin to be actuated by a key and a key to loosen and tighten the referred-to pin, particularly where the key is a magnetic key.

BACKGROUND OF THE INVENTION

[0002] Under Patent n° AR003791B1 is disclosed a safety pin composed of a threaded rod ending at its upper end in a safety head, surrounded by a fixed head, integrated into the extremity of the rod and by a movable head, i.e., mounted freely rotating and concentric to the fixed head; both heads, the fixed and the movable ones, are placed coaxially and concentrically at the extremity of the rod with a freely rotating connection of the movable head facing an undue attempt to actuate the pin, or by the use of conventional keys or tools.

[0003] The heads, the fixed and the movable ones, limit between themselves a longitudinal cavity in the safety head of the pin concentric to the same, for sheltering an annular body related to the lateral surface of the cavity by mutually cooperating locking means, in order to permit an axially free movement at the same. This annular body has an axial perforation with stepped-up circular and rectangular cross section proportions, respectively, the upper portion forming a seat and partial shelter of the extreme portion of a spring, whose opposite extremity is supported against the internal surface of the basis of the movable head, surrounding a coaxial opening to the geometrical axis of the rod of the pin, the referred-to basis of the movable head presenting blind holes, radially opposed with relation to the opening.

[0004] The main request discloses also a special key to actuate, tighten or loosen the pin, constituted by a pair of telescopically mounted bodies, one of which, the upper one, is constituted by a bar presenting a cavity for a spring supported at its bottom and at the bottom of the cavity of the other body mounted with telescopic displacement, a rod being projected from the bottom of the first cavity beyond the free extremity of the lower body, terminating in a rectangular cross section hammered hooking piece, coinciding with the lower rectangular cross section portion of the passing perforation of the input annular body of the pin heads. The lower body of the key has in concentric form the bearing rod of the hammered hooking piece, eyebolts for inserting into the blind holes of the movable head and the upper body of the key at its free extremity, a grip to exercise a tightening or loosening torque of the pin.

[0005] As stated in the main request, in order to actuate the pin, the key shall be presented and the hammered hooking piece fixed to its upper body be introduced, and simultaneously the eyebolts of the lower body shall be inserted into the blind holes of the upper basis of the movable head; thus, the upper body or the bar which bears the grip for the referred-to hooking piece shall be inserted into the stepped-up perforation portion of the annular input body of the head, so that the extremity of the rectangular cross section coupling part is positioned below the annular body and can be rotated by 90° in order to be inserted into lower locking and dragging slots of the referred-to annular body.

[0006] This permits that the spring confirmed in the key prevails over the load spring of the annular body of the head of the pin, overcoming the same and causing the dislocation of the referred-to body to a locking position of the fixed and movable heads of the pin in order to actuate the same.

[0007] As can be appreciated, this pin and key assembly described in the main request complies with its purpose, it is noted that the same needs for its creation a precision mechanism in order to move its components (rod with disengagement means, perforation of different cross sections in the annular locking body in the safety head, springs in this body and the key, with different tensions, etc.); and also the application of the key for actuating the pin requires a series of previous steps to be complied with by the user for performing the torque.

SUMMARY OF THE INVENTION

[0008] The invention provides a pin and key assembly incorporating a new means for the reciprocal mechanical and magnetic coupling of the pin and key during its tightening or loosening relation of the referred-to pin and thus, to overcome the friction resistance at the application point of the pin.

[0009] The invention also provides for the incorporation into the referred-to pin, of a locking means, by attraction of the magnetic force of the permanent magnet of a key, carrying simultaneous coupling eyebolts with orifices of the movable head of the pin, in answer to the application of the key on the safety head of the pin.

[0010] The invention further provides on safety pins and special actuating keys of the same, a means of coupling the safety head of the pin and the mechanical or magnetic combined key, in order to exercise thereby through the key stem a torque in the pin for its tightening or loosening.

[0011] Still further, the invention provides the incorporation of a locking means for the movable head of the pin in the limiting cavity, constituted by a sliding body of magnetic material, laterally locked in the referred-to cavity for its free axial movement against a spring and in answer to the application of a key bearing a permanent magnet of paramagnetic material configured in a tubular cover and capable to link to the movable head, by means of a carrier of magnetic material, the mechanically connecting eyebolts to the movable head.

[0012] The invention includes a safety pin and a special actuating key of quick and simple application by inserting the eyebolts into the orifices of the movable head, and support of the bearer, permeable to the magnetic field of the key, which for its part exercises a magnetic attraction force on the sliding locking body of the fixed and movable heads of the pin.

[0013] Also the invention offers a combination of means, in the pin and the key, in order to couple the movable head of the pin to the fixed head operating mechanically and magnetically, in order to permit the application of the torque required to tighten or loosen this type of pin with a rotating movable head, destinated to inhibit the use of conventional keys.

[0014] For the purpose of improving the pin and key assembly described in the main request, the present invention proposes improvements of the same, destinated to structurally simplify the pin and the key, offering at the same time an automatic actuation of the latter, based on the effects of the magnetic force of a permanent magnet incorporated into the key, which determines the elimination of previous movements or positionings of the key in order to actuate the pin, and which are indispensable to operate the assembly disclosed in the main request.

[0015] According to the invention, the safety pin comprises in the cavity formed by the parts constituting the fixed head and the movable head, a sliding body of magnetically attracting material, which has a blind hollow part, whose bottom constitutes the seat of one extremity of its load spring, whose opposed extremity is supported directly against the basis of the movable head which only at its exposed surface presents the blind holes for the eyebolts of the key.

[0016] This latter is constituted, for its turn, by a tubular body of paramagnetic material, which extends on the upper side by means of a portion terminating in a grip support, presenting at the lower extremity of the referred-to tubular body of paramagnetic material a permanent magnet in contact with a closing of material permeable to the magnetic field and bearing a small head with inserting eyebolts into the blind orifices of the movable head.

[0017] The application of the key on this latter one determines by magnetic attraction the movement of the sliding locking body of the head of the pin, locking the parts of the same which form the fixed and movable heads, permitting the application of a torque on the pin, to be tightened or loosened.

BRIEF DESCRIPTION OF THE DRAWINGS

[0018] (FIG. 1) represents the corresponding elevation views of the pin and key.

[0019] (FIG. 2) represents the referred-to pin partially in a cut view, with its movable head confronting the key.

[0020] (FIG. 3) represents a view similar to the one of (FIG. 2), but with the key in the position connected to the pin, showing the locking of the fixed and movable heads of the latter by magnetic effect; and a detail in larger scale of the locking position of the safety head prior to be submitted to a torque.

[0021] (FIG. 4) represents a horizontal projection of the movable head of the pin, which may present variable amounts (3-4-5-6-etc.) of symmetric or asymmetric perforations.

[0022] At last, (FIG. 5) represents a cut along the line (1-1) of (FIG. 1), showing different variants which may be adopted by the lateral surfaces of the cavity of the head of the pin and of the sliding body, in order to avoid rotating effects during their movement.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0023] According to the presentation of the drawings, particularly at (FIGS. 1 to 3), where, as presented as an assembly, the pin (a) as in the main request, is comprised by a threaded rod (1) with a safety head (c), totally connected by a conical portion (2) to the rod (1).

[0024] The safety head (c) is constituted by a part (3) emerging from the portion (2) and presents a hollow cylindrical part (4); and by a movable part (11) in the form of a bushing, with a complementary hollow part (4′) in order to delimitate in the referred-to head (c) an axial cavity (4-4′). The part (3) fixed to the rod (1) and the movable part (11) surround the corresponding fixed and movable heads at the pin, which are related at their connecting extremities by a slot and an eyelash (8), complementary and freely rotating in relation, permitting the rotation of the movable part (11) facing an undue attempt to loosen the pin (a).

[0025] The head or movable part (11) has, according to the invention, an upper passage (11′), with only blind orifices (12), or variable symmetrical or asymmetrical amounts, and at its lower face (11′a) it constitutes the support for the extremity of a load spring (10) for the body, which constitutes the locking means for the parts (3) and (11) of the safety head (c).

[0026] This body (5), as represented in (FIG. 5), may be prismatic and of polygonal cross section (square, pentagonal, hexagonal or octagonal), as indicated at the cuts by the line (1-1) of (FIG. 1), represented on (FIG. 5) with references A-B-C and D. The facetted lateral surface of the body (5) corresponds to the lateral surface of the cavity (4-4′), i.e. this latter one shall present in a cross section an equal cross section, in order to permit an axial and free movement of the body (5) to its locking position of the parts (3) and (11).

[0027] (FIG. 5) in the example B exposes another variant of realizing the body (5), where a cylindrical conformation with a passing device (p), transversal to the body (5) is adopted, which permits to be guided in an axial form in grooves (r) of the cylindrical lateral wall of cavity (4-4′).

[0028]

[0029] The body (5), in all realizations, comprises a blind hollow part (9) for supporting the extremity of spring (10), whose opposed extremity is supported at base (11′), also blind, of the movable part (11) of head (c).

[0030] The key (d) actuating the pin (a) described, is constituted by a tubular body (14), terminating on the upper side in a head (15), provided with a grip or transversal bar (18), in order to permit the manual actuating of the key (d).

[0031] The tubular body (14) according to the invention presents a lower portion (14′), where a permanent magnet (16) is confined and therefore this portion (14′) is of insulating material, i.e., paramagnetic material, so that the magnetic field of the magnet (16) can exercise an attraction by means of a support (17) of eyebolts (12′), which, as in the case of the main request, shall be introduced into blind orifices (12) of the base (11′) of the movable piece (11) or movable head of the pin (a).

[0032] In order to actuate the pin (a), according to the invention, the key (d) is coupled mechanically by insertion of the eyebolts (12′) into the blind orifices (12) of the movable piece (11). This permits the simultaneous coupling of the permanent magnet (16) at the base (11′) of the referred-to part (11), so that the magnetic material with which the movable part (11) is constituted, and the support (17), due to their magnetizing capacity, exercise an attraction of the locking body (5) of parts (3) and (11) of the safety head (c) in opposite position to the spring (10), obtaining a connection of these parts (3-11) in order to permit exercising a torque on the pin (a) by means of the grip (18). The removal of the key (d) permits the body (5) to return to its inoperant position by action of the spring (10).

[0033] As can be appreciated, the actuation of the pin (a) and the structural characteristics of the pin and the key, which are described in the main request, were simplified. 

1. A safety pin to be actuated by a key comprising: parts, fixed and movable, which surround a head of a rod, limiting by means of their respective semi-hollow parts a totally closed cavity in said head for sheltering a body, mounted axially and enabled to slide inside said cavity and under demand of an elastic means, whose extremities are supported on an upper wall of the movable pieces provided with blind orifices for insertion of eyebolts of the key, and constituted by a magnetic material and, on the other side, at a bottom of a blind hollow part of said body, enabled to move the head axially, also of magnetic material, surrounding an upper part of the movable head of the rod with its blind orifices, a connection and supporting means for coupling the permanent magnet of the key, capable of exercising a magnetic attraction on said body through an upper wall of the mobile part, for locking said fixed and movable parts of the head.
 2. A pin according to claim 1, wherein said body enabled to slide axially of the head of the pin includes a prismatic part presenting a polygonal cross section corresponding to a cross section of the closed cavity of the head, said head presenting a cylindrical blind hollow part, against whose bottom is supported an extremity of the elastic load means against the bottom of the cavity.
 3. A pin according to claim 1, wherein said body enabled to slide axially of the head of the pin includes a cylindrical part having at least one transversal passer with extremities projecting from the said part at diametrally opposed points of the same, and which are inserted, respectively, with free play, in corresponding longitudinal grooves of a lateral surface of said cavity, in order to surround guidance means of said part, in answer to the magnetic attraction force of the magnet of the key, said part presenting a cylindrical hollow part for said spring.
 4. A key to loosen or tighten a pin as defined in claim 1, comprising: a rigid tubular body presenting an upper portion terminating in a head which bears a manual actuating grip, and an inferior portion of larger diameter and of paramagnetic material, where a permanent magnet, supported upon a head of magnetic material, bearing connecting eyebolts of mechanical connection with the movable parts of the head of the pin, is mounted in fixed form on an extreme free portion of the tubular body. 